Spring hinges

ABSTRACT

The invention relates to a spring hinge for eyeglasses with a spring member and a housing at least partially receiving the hinge member and which is open at one end surface thereof, with a closing member (13) fixedly retained in the housing (3) and having a run-on surface (38), which closes the end surface of the housing, and with an opening having guide surfaces (19, 21, 23) and extending through the closing member (13) for receiving the hinge member (11).

The present invention relates to a spring hinge for eyeglasses andhaving a housing which receives a spring member and at least a portionof a hinge member.

Spring hinges of this type are known. They generally include a housingin which a spring member is received. The spring member provides forpivoting of an ear-piece connected with the spring hinge into a wearposition and applies to the ear-piece a preload with which the ear-pieceis pressed against the head of a glasses wearer. However, in certaincases, the manufacturing of the spring hinge proved to be ratherexpensive, which is a disadvantage.

Namely, machining of the inner space of the housing, in which the springmember was received, was necessary, which particularly in view of thesmall dimensions of the housing, required high precision and is,therefore, expensive.

It also turned out that guiding characteristics of such housing are notalways satisfactory. It could also happen that the hinge member, whichis connected with the ear-piece, was not reliably secured and,therefore, became loose. Relatively very extensive constructional costsare involved in the elimination of this drawback.

In addition, in spring hinges with a snap action, displacement of cams,which are present in the middle portion of the hinge, along an endsurface of the housing presents a problem. In particular, the materialcharacteristics of this run-on surface are adversely affected by heatingrequired for soldering of the housing on the ear-piece. This results inthat the run-on surface cannot sustain the cam pressure, applied to itfor a certain time, and wears off, becoming damaged. Therefore, areliable run-on cannot be insured any more.

Accordingly an object of the invention is a spring hinge which can be,on one hand, inexpensively produced and, on the other hand, ischaracterized by good guiding characteristics. In addition, the run-onsurface should not lose its run-on characteristic upon being subjectedto an extended pressure action.

This object is achieved in a spring hinge having the features recited inclaim 1. Because the housing serves for receiving a closing member,which guides the hinge member and forms a run-on surface independentfrom the housing, the construction of the housing is simpler, on onehand, and on the other hand, a reliable guide for the hinge member and arun-on surface, the material of which is selected independent of thehousing material, can be formed in accordance with specificrequirements.

In addition, the object of the invention is achieved by a manufacturingprocess having features recited in claim 11. Because the housing, theclosing member and/or the hinge member are stamped and/or formed from asimple and very inexpensive material, the manufacturing is very simpleand cost-effective. In particular, expensive profiles and machiningsteps, such as milling or drilling, can be completely eliminated.

A further advantage results from using a material having a uniformthickness for manufacturing the housing. Then, in effect, the housingwalls have a substantially the same thickness whereby, e.g., softeningof the thinner regions during inductive heating of the housing isprevented.

Especially advantageous is an embodiment of a spring hinge in which theclosing member, together with spring and hinge members received in thehousing, is formed as a pre-assembled unit that can be easily insertedinto the housing, already mounted on the ear-pierce of eyeglasses. Thefinal assembly of a so formed spring hinge is, thus, simple and,therefore, can be economically effected.

Further embodiments of the spring hinge are set forth in furthersubclaims.

The invention will be explained below on the basis of the drawings. Inthe drawings:

FIG. 1 is a cross-sectional view of a first embodiment of a springhinge;

FIG. 2 is a plan view of the spring hinge shown in FIG. 1;

FIG. 3 is a longitudinal cross-sectional view of a closing elementarranged in a housing of the spring hinge shown in FIG. 1;

FIG. 4 is a front view of the closing member shown in FIG. 3;

FIG. 5 is a plan view of the closing member shown in FIGS. 3-4;

FIG. 6 is a cross-sectional view of another embodiment of a springhinge;

FIG. 7 is a bottom view of the spring hinge shown in FIG. 6;

FIG. 8 is a perspective view of the closing member of the hinge spring;

FIG. 9 is a cross-sectional view of a further embodiment of a springhinge;

FIG. 10 is a bottom view of the spring hinge shown in FIG. 9;

FIG. 11 is a longitudinal cross-sectional view of a closing element forthe spring hinge shown in FIG. 9;

FIG. 12 is a bottom view of the closing member shown in FIG. 11;

FIG. 13 is a cross-sectional view of a still further embodiment of aspring hinge;

FIG. 14 is a cross-sectional view along line A--A in FIG. 13; and

FIG. 15 is a perspective view of a closing member used with the springhinge shown in FIG. 13.

The spring hinges of the above-described type are used for connecting ofthe ear-pieces of glasses to a middle section of the glasses. As a rulethe spring hinge is attached to the ear-piece, and has a hinge membercooperating with the hinge of the middle section of the glasses topivotally connect the ear-piece with the middle section. The ear-piececan be moved from its original position into its wear position, with thespring member of the spring hinge applying a return force.

The spring hinge 1 according to the present invention, which is shown inFIG. 1 showing its longitudinal cross-section, includes a housing 3 thatis produced of a deformable material, e.g., metal, by a deep-drawingprocess, preferably by an embossing process. The process, which is usedfor manufacturing of the housing 3, will be described in detail belowwith reference to FIG. 16. The housing 3 is open at its bottom 5. Aspring member 7, which is formed as a helical spring, is located in thehousing 3 and is supported on an elongate extension 9 of a hinge member11. The extension 9 is formed as an elongate pin that extends throughthe helical spring and is widened at its end by, e.g., by crimping, sothat an abutment for the helical spring is formed. At its opposite end,the helical spring, i.e. the spring member 7, abuts a closing member 13which is located in the housing and through which the hinge member 11extends. The closing member 13 is completely received in the housing 3.The hinge member 11 has a gudgeon 15 at its end projecting out of thehousing 3. The gudgeon 15 cooperates with a hinge provided on the middlesection of the glasses (not shown). The spring member 7 and the closingmember 13 are so dimensioned that no part of the spring member 7 and theclosing member 13 projects through the bottom 5 of the housing 3.Rather, the surfaces of the spring member 7 and the closing element 13are made flash with the bottom surface of the housing 3 which issupported on an outer surface of the ear-piece and is fixedly attachedthereto, e.g., by soldering.

The gudgeon 15 and the hinge member 11 are formed as one piece. Theextension 9 is also a part of the hinge member 11, so that the number ofelements forming the spring hinge according to the present invention isreduced to a minimum. After the spring member 7, which is formed as ahelical spring is mounted on the extension 9 the end of which is thencrumped, the spring member 7 and the hinge member 11 form a unit.

Because the closing element 13 is aligned with the bottom 5 of thehousing 3, the bottom of the closing element 13 lies flatly on the outersurface of the ear-piece when the housing 3 is secured to the ear-piece.On the other hand, the closing member 13 is supported, adjacent to theend surface of the housing 3, against the housing inner surface 17. Inan assembled condition of the hinge 1, the closing member 13 isoptimally retained in the housing 3.

The closing member 13 has a smooth inner surface 19 on which the hingeelement 11 lies. The inner surface 19 serves as a first guide surfacefor the hinge member 11 which is displaceable against the biasing forceof the spring member 7. The second guide surface 21 is formed as aresult of the hinge member being surrounded, at least partially, by theclosing element 13. The third guide surface 23 is formed by an innersurface portion of the closing member 13 which is engaged by arespective surface of the hinge member 11.

The gudgeon 15 is so dimensioned that its stop shoulder 25 abuts an endsurface 35 of the housing 3, which thus serves as a stop surface, whenthe hinge member 11 is drawn to the end surface 35 of the housing 3 bythe preloaded spring member 7.

Because the hinge member 11 extends through the closing member 13 andbecause the spring member 7, which is supported against the widerportion 9 of the hinge member 7, applies a preloading force to the hingemember 11, there is provided a ready-to-be-used assembly consisting ofthe hinge member 11 the spring member 7, and the closing member 13.

The assembly is inserted into the housing 3 after the housing 3 isattached to the ear-piece, e.g., by welding or soldering. The closingmember is provided with a catch nose 27 hingedly attached to the body ofthe closing member 13 and which engages the opening 29 provided in thewall of the housing 3. The abutment shoulder 31 of the catch nose 27prevents the catch hose 27 from projecting out of the opening 29 of thehousing 3 and insures that the outer surface of the catch nose 27 isflash with the outer surface of the housing 3.

Generally, the opening 27 can be formed as depression in the wall of thehousing 3 into which the catch nose extends thereby providing forretaining of the closing member 13 in the housing 3. In the embodimentof the spring hinge shown in FIG. 1, the opening or recess 29 extendsthrough the entire thickness of the housing wall so that the catch nose27 is accessible from outside and, therefore, can be easily disengaged.The catch nose 27 is connected with the body of the closing member 13 bya spring arm 33.

FIG. 2 shows that the gudgeon 15 projects from the end surface 35 of thehousing 3 and is narrower than the latter. FIG. 2 also shows that theopening 29 for receiving the catch nose 27 is square. The dimensions ofthe opening 29 and the catch nose 27 are so selected that the inside ofthe housing 3 is protected from the penetration of dirt thereunto.Corresponding, the dimensions of the closing element 13 are selected tolikewise prevent the penetration of dirt into the inside of the housing3 from the housing end surface 35.

FIG. 3 shows the closing member 13 in a non-assembled condition. Here,the inner surface 19 serves as a guide surface for the hinge member 11.In addition, the inner surfaces of the closing member 13 include asecond guide surface 21 and a third guide surface 23. The guide surfaces19, 21 and 23 so cooperate with each other that the hinge member 13 isdisplaced in the interior of the closing member 13 practicallyclearance-free. This insures an optional displacement of the hingemember 11 in the inferior of the housing 3.

FIG. 3 also clearly shows the arm 33, which was discussed with referenceto FIG. 1 earlier, with the catch nose 27 and the abutment shoulder 31.

The inner dimensions of the closing member 13 are so adapted to those ofthe hinge member 11 that the hinge member 11, as it has already beendiscussed above, is displaced practically clearance-free.

The front view of the closing member 13, which is shown in FIG. 4,demonstrates that practically a square passage 37 is formed between theguide surfaces 19 and 21 through which the hinge member 11, whichpreferably has a likewise square section corresponding to this passage,extends. FIG. 4 also shows a third guide surface 23. In addition, FIG. 4shows an end surface 38 which defines its run-on surface. The exactfunction of which will be discussed below.

The shape of the closing member 13 is adapted to the inner profile ofthe housing 3, so that, in an assembled condition of the spring hinge 1,the bottom 39 of the closing member 13 lies on the outer or uppersurface of the ear-piece, with the top surface 41 abutting the innersurface 17 of the housing 3 and the side surfaces 43, 45 abuttingrespective inner side surface of the housing 3. In the assembledcondition of the spring hinge 1, the closing member 13 is, thus,retained in the interior of the housing 3 practically clearance-free.

FIG. 4 also shows that the closing member 13 encloses the hinge member11 from all sides, whereby a unitary structure described above, isformed.

The plan view of the closing member 13, which is shown in FIG. 5,demonstrates that the width of the catch nose 27 is smaller that thewidth of the closing member 13 itself. The spring arm 33, which supportsthe catch nose 27 can be formed as a continuous bridge. However, asmaller arm can be used or, as shown in the shown embodiment, twosubstantially V-shaped spring arms 33 can resiliently connect the catchnose 27 with the body of the closing member 13.

The catch nose 27, which according to FIG. 1 or 3 has an upper surfacewhich is formed as a inclined surface. It forms a quasi snap connectionthat holds the assembly, which is formed of the spring member 7, hingemember 11, and the closing member 13 in the interior of the housing 3.The catch nose 27 in held in the opening 29 of the housing 3 due tospring action of the spring arms 33.

The hinge member 11 as well as the closing member 13 are preferablyformed of metal, in particular of nickel-free metal, preferably oftitanium. This prevent an allergic reaction in a glasses wearer, on onehand, and on the other hand, reduces wear.

FIG. 6 shows another embodiment of a spring hinge according to thepresent invention. In FIG. 6, the same reference numeral will be usedfor parts corresponding to the identical parts of the hinge spring shownin FIGS. 1-5. In the embodiment shown in FIG. 6, the spring hinge 101has likewise a housing 3 in which a closing member 13 is received. Ahinge member 11 extends through the closing member 11 and has anelongate extension 9 which extends through a spring member 7 which isalso formed as a helical spring. The spring member 7 is supported at oneend by the closing member 13 and, at the other end, by a stop ring 47supported on the extension 9 of the hinge member 11 and is retained,e.g., by a widened portion formed at the free end of the hinge member 7.The spring member 7 is mounted on the extension 9 in a pre-loadedcondition so that the hinge member is so drawn into the closing member13 that the gudgeon 15 is drawn to the end surface 35 of the housing 3and to the end surface of the closing member 13.

The housing 3 is so formed that neither the spring member 7 nor thehinge member 11 projects through the bottom 5 of the housing 3. Thus,when the housing 3 is mounted on a earpiece, e.g., is sodded thereto,the bottom of the closing member 13 flatly lies on the upper surface ofthe ear-piece. The top surface of the closing member 13 abuts the innersurface 17 of the housing 3 so that in the assembled condition of thespring hinge the closing member 13 is reliably held in the interior ofthe housing 3 and forms a guide for the hinge member 11. The hingemember 11 has its surfaces supported on first and second guide surfaces19 and 21 located adjacent to the support surface for the spring member7. Closely to the end surface 35 of the housing 3, the closing member 13has an inner guide surface 23 which is located opposite the first guidesurface 19. The distance of the third guide surface 23 from the firstguide surface 19 is greater than the distance of the second guidesurface 21 from the surface 19 the hinge member 11 in this region has agreater height.

Preferably, the hinge member 7 is formed as a bent member, namely, as anelongate wire part which forms, in the gudgeon region, an eyelet havinga backward extending portion which is supported against the third guidesurface 23. The hinge member 11 of this embodiment can be produced veryeconomically. A discussion of manufacturing of the hinge member 11 willbe made below with reference to FIG. 17.

From the bottom view of FIG. 7, it can be seen that the strop ring 47 issupported against inner surfaces of the housing 3 and, thus, can bereliably guided along the extension 9. The side walls of the closingmember 13 adjoin the sides of the housing 3, insuring a reliable guidingof the closing member 13 in the housing 3.

The closing member 13 has two catch noses 27a and 27b which areresiliently supported by spring arms 33 on the body of the closingmember 13. The catch noses 27a and 27b engage in openings 29 provided inside walls of the housing 3. Generally, the openings 29 are formed asindentations in side walls of the housing 3 in which the catch noses 27aand 27b engage. In the embodiment of FIG. 6, the openings 29 are formedas through openings, and the outer surfaces of the catch noses 27a and27b are flash with the side outer surfaces of the housing 3 when thecatch noses 27a and 27b engage in the openings 29. Thus, a visualappearance of the spring hinge 101 is no way disturbed, and the catchnoses 27a and 27 are easily accessible for possible removal of theclosing body 13. The catch noses 27a and 27b are engaged in the openings29 with a snap action. The locking action of the spring arms 33 isassisted by the spring action of the spring member 7 which acts on innersides of the catch noses 27a and 27b so that they are biased outwardlyin the openings 29. When the ear-piece is overstretched, the hingemember 11, which is displaceable in the housing 3 against the biasingforce of the spring member 7, is drawn out of the housing 3, and thespring member 7 becomes compressed. Thereby, the spring forces, whichact in a locking direction of the catch noses 27a and 27b, increase, andas a result, the anchoring of the closing member 13 in the interior ofthe housing is insured when the spring hinge is loaded.

In the embodiment of FIG. 7, the bottom of the closing member 13 ispractically closed. In this embodiment, the closing member 13 isprovided with two slots 53 which define the spring arms 33 which connectthe catch noses 27a and 27b with the closing member 13.

FIG. 8 shows a lighter closing member 13 which is characterized in thatits bottom is open. In this embodiment, the hinge member, which is notshown in FIG. 8, is guided by the second and third guide surfaces 21 and23 shown in FIG. 6 on one hand, and by an upper surface of an ear-piecewhich support the closing member, on the other hand.

The perspective bottom view of the closing member 113, clearly shows theshape of the catch noses 27 and 27b, which have a somewhat conicalsurface that provides for the above-discussed snap connection when thecatch noses 27a and 27b are pushed outwardly by the spring arms 33.

The bottom 39 of the closing member 113 is made even so that it flatlylies on an upper surface of an ear-piece, insuring an optimal guidanceof the hinge member 11.

The spring hinge of the embodiments of FIGS. 1 and 6 is characterized inthat the unit, which is formed of the hinge member, spring member andthe closing member and is inserted into the housing secured on theear-piece, can be removed as necessary because the catch noses of theclosing member are accessible from outside when the spring hinge issecured to the ear-piece.

FIG. 9 shows another embodiment of a spring hinge 201 which has ahousing 3, with the spring member 7 and the hinge member 11 beingreceived in the housing interior. The hinge member 11 has an elongatedextension 9 and a gudgeon 15 both forming parts of the one-piece hingemember 11. The hinge member 11 extends in the closing member 13 whichsurround the hinge member 11 at least as a horseshoe.

As shown in FIG. 10, the housing 3 differs from the housing of theembodiments of FIGS. 1 and 6 in that it has a bottom 55 which enclosesthe assembly formed of the spring member 7, hinge member 11 and theclosing member 13.

The closing member 13 is likewise provided with the catch nose 27engaging in an opening 29 of the housing 3. In this embodiment, theopening 29 is formed in the bottom 55. Thus, after the spring hinge 102is mounted on an ear-piece, the catch nose 27 is not accessible anymore. The interior of the housing 3 is better protected from dust anddirt as well as from the waste resulting from soldering of the housingto the ear-piece. The spring member 7 is supported at one end thereofagainst a stop ring 47 secured on the extension 9 of the hinge member11. The stop ring 47 is prevented from being dislodged by thedeformation of the end portion of the extension 9.

The hinge member 11 lies with its bottom flatly on the inner surface ofthe bottom 55 which forms a first guide surface. The second guidesurface 21 is formed adjacent to the spring member 7, and the thirdguide surface 23 is formed adjacent to the end surface of the housing 3.Providing these three guide surfaces insure a reliable guidance for thehinge member 11 in the closing member 13. The interior dimensions of theclosing member 13 are so matched with those of the hinge member 11 thatan optimal guidance of the hinge member 11 in the closing member 13 isinsured.

Between the end surface of the housing 3 and the hinge gudgeon 15 whichhas a stop surface 25, a closing plate 57 can be provided for preventingthe penetration of dirt into the interior of the housing 3.

As it is clearly seen in FIG. 10, the hinge member 11 is smaller thanthe housing 3. FIG. 10 further shows that the opening 29 is athrough-opening which surrounds the catch nose 27 from all sides.

FIG. 11 shows a longitudinal cross-section of the closing member 13. Aspring arm 33, which connects the catch nose 27 to the body of theclosing member 13, formed, as shown in FIG. 11, by a bar separated fromthe body of the closing member 13 by a slot 59. As shown further in FIG.11, the closing member 13 can be provided with a bead 61 which servedfor closing the end surface of the housing 3 and can be used instead ofthe closing plate 57 shown in FIG. 9. In this case, the closing memberforms a stop or the hinge member 11 and provides for a particular goodguidance of the hinge member 11 in its interior.

The spring arm 33 can have its inner surface formed as a run-on inclinedsurface to which the spring member 7 applies a downward directed loadingforce displacing the catch nose 27 into its locking position. When thehinge member 11 is axially displaced leftward, in FIG. 9, the springmember applies an increased biasing force to the catch nose 27 providingfor its better anchoring in the opening 29 in the bottom 57 of thehousing 3.

As shown in FIG. 12, the width of the catch nose 27 is smaller than thewidth of the closing member 13, whereas the width of the bead 61 exceedsthe width of the closing member 13, insuring closing of the end surfaceof the housing 3, with the run-on surface 38 on the cross-section of thehousing 3 at the end surface being increased.

In the second and third embodiments, the housing is formed of adeformable material, preferably a material which can be deep-drawn. Theclosing member and the hinge member can be formed of plastic materials.However, preferably, a nickel-free material, such as titanium, is usedfor manufacturing the closing and hinge members.

FIG. 13 shows a yet another embodiment of a spring hinge 303 having ahousing 3 with a bottom 55. A spring member 7, which is formed, e.g., asa helical spring, is received in the housing and is displaced on theelongate extension 9 of the hinge member 11 and is supported against astop ring 47 supported by a widened portion of the extension 9. The stopring 47 forms a first stop for the spring member 7, with the closingmember 213 defining another stop.

The closing member 13 (should be hinge member 11 translator's remark) isprovided with a gudgeon 15 which projects from the housing 3 and thedimensions of which are so selected that the stop surface 25 of thegudgeon 15 abuts the end surface of the housing 3. With the springmember being preloaded, the gudgeon 15 is pressed against the endsurface of the housing 3.

The bottom 55 of the housing 3 has a through-opening 29 in which a catchnose 27 of the closing member 213 engages. The closing member 13 isformed as a bent sheet material piece. The closing member 213 providesguide surfaces for a horizontal displacement of the hinge member 11against the biasing force of the spring member 7. The closing member 213has an opening 65 the circumference surface of which is so matched withthe profile of the extension 9 of the hinge member 11 that thecircumference surface forms a hinge displacement guide.

The closing member 213 has its upper surface flatly lying on the innersurface 17 of the housing 3 and its bottom side lying on the innersurface of the bottom 55 of the housing 3, which insures an optimalretaining of the closing member 213 in the housing 3.

FIG. 14, shows a cross-section along line A--A in FIG. 13, in which theouter surfaces of the closing member 213 all lie on the respective innersurfaces of the housing 3 so that the closing member 213 is surroundedfrom all sides by the inner surfaces of the housing 3, whereby theclosing member 213 is reliably contained in the housing 3. The closingmember 213 has, at a bottom thereof, two side arms 67 and 69 the innersurfaces of which serve as guides for the hinge member 11. The bottom 39of the closing member 213 flatly lies on the bottom 55 of the housing 3,insuring appropriate guiding of the hinge member 11.

FIG. 15, shows a principle perspective view of a closing member 213shown in FIGS. 13-14. The closing member 213 has arms 67 and 69, theadjacent inner surfaces of which abut the outer side of the hinge member11 and form guide surfaces. FIG. 15 also shows an opening 65 throughwhich the extension 9 projects and the inner surfaces of which formguide surfaces for the extension.

The side arms 67 and 69 serves as spring arms for the catch nose 27which reliably retains the closing member 213 after its insertion intothe housing 3.

In the above-shown embodiments, the hinge member 11 has a gudgeon 15 andan extension 9. Because the hinge member 11 in all of the embodimentsextends through the closing member, the spring member 7, the hingemember 11, and the closing member 213 form a unitary assembly that caneasily be inserted into the housing 3.

In the embodiments in which the housing 3 has a bottom 55, the unitaryassembly of a spring is inserted in the housing 3 before the housing issecured to an ear-piece whereby a spring hinge assembly is formed. Then,the housing 3 can be secured on the ear-piece in any suitable manner,wherein, in view of spring characteristics of the spring hinge assembly,gluing is a preferable method. When soldering or welding on anear-piece, the unitary assembly is inserted in the housing after thehousing is secured on the ear-piece. This prevents the closing memberfrom being subjected to the heat, associated with soldering or welding,which would adversely affect the steadiness of the run-on surface of theclosing member.

In the transition region between the side or spring arms 67, 69 and thecatch nose 27, an inclined surface 71, as shown in FIG. 15, is provided.When a spring force is applied to the arm 73 of the closing member 213,the arm 73 is pressed against the inclined surface 71, pressing thecatch nose 27 downward, further into its locking position. Thus, when anadditional load is applied to the spring member 7, as a result ofdisplacement of the hinge member 11 leftward, the locking action of thecatch nose 27 is increased by the run-on inclined surface 71. The springhinge 303, shown in FIGS. 13-15, is characterized by an especiallyeconomical manufacturing of the closing member 213, which can bereliably retained in the spring hinge housing 3, with the upper surface41 of the closing member 213 firmly abutting the inner surface 17 of thehousing 3 and with bottom surfaces of the arms 67, 69 flatly lying onthe inner surface of the bottom 55 of the housing 3 (see FIG. 3). Due tothe reliable retention of the closing member 213 in the housing 3, anoptimal guidance of the hinge member 11 is insured even when the closingmember 213 is formed from a sheet material insuring the inexpensivemanufacturing of the closing member.

In case of the unitary assembly of the spring, hinge and closing membersbeing inserted in a housing having a bottom with an opening in which thecatch nose of the closing member engages for retaining the unitaryassembly in the housing, after the housing is secured on the ear-piece,the unitary assembly cannot be withdrawn from the housing any morebecause the catch nose is not accessible from the outside. If the springhinge is formed as a prefabricated unit and then is secured on anear-piece, the catch nose remains accessible before the unit is securedon the ear-piece. In this case, the unitary assembly of the spring,hinge and closing members can be withdrawn from the housing.

In all of the cases, the simple construction of the unitary assemblyinsures its easy mounting in a housing secured or securable on anear-piece, a reliable retaining of the closing member in the housing,and at the same time, optimal displacement of the hinge member in thehousing. In addition, the closing member is provided with a run-onsurface with optimal characteristics which are not adversely affected bytempering during soldering or welding of the housing to an ear-piece.

In all cases, a simply manufactured stamping can be used as a housingwhich insures economical manufacturing of the spring hinge. Because theclosing member is surrounded by the housing at least from three sides,with the fourth side being closed by an ear piece, dust, lacquer and/orpolishing compounds cannot penetrate into the spring hinge, whichinsures a very high functionality of the spring hinge. Because the endsurface of the housing is also practically completely closed by theclosing member and firmly abuts an ear-piece, a spring hinge completelyprotected from any penetration of dirt is produced, without anysubstantial expenses. Also, the use of the closing member for guiding ofthe hinge member further reduces the constructional expenses and themanufacturing costs.

As it has already been mentioned, the housing and the hinge member areeconomically produced from a metal strip by stamping and shaping eachconsisting only of a few operational steps. Machining operations are notanymore necessary.

Also, the closing member described in the specification can be produced,in a similar manner as the housing and the hinge member, from a metalstrip, with the use, preferably, of pressing and die stamping, e.g.,bending. Here also preferably, a nickel-free metal, e.g., titanium isused.

The smaller dimensional accuracy of the stamping and shaping technology(in comparison with the conventional machining) can be compensated byinsertion of an appropriate closing member. From the description, it isclear that the manufacturing of the above-mentioned parts is very simpleand, therefore, extremely cost-effective. Expensive profiles, from whichthe housing and the hinge member were cut-out, are eliminated. Also, thenecessary machining of the cut-out profiles is eliminated by theforegoing manufacturing processes.

The spring hinge shown in FIGS. 1-15 is characterized in that the hingemember which, together with the spring and closing members, form aunitary assembly is easily insertable into the housing and is reliablysecured therein, and in that closing member is formed as a snap-lockingelement. Upon the insertion, the unitary assembly is locked in thehousing, without any need for other connecting means which makesassembling of the spring hinge more expansive.

Despite an easy assembly, a very exact guidance of the hinge member isachieved because it is guided entirely through the closing member. Inthe embodiment shown in FIG. 8, the guiding of the hinge member isinsured by forming the closing member as a U-shaped member, with thehinge member flatly abutting the ear-peace on which the spring hinge ismounted. Thus, guiding of the hinge member on all sides of the hingemember is insured.

An especially good guiding of the hinge member is insured when thegeometrical parameters of the closing member, length L, height H and thewidth B, have the following relationship: L>H>B. These dimensionsinsure, on one hand, a reliable retaining of the closing member in thehousing, insuring a clearance-free seating of the closing member in thehousing, and, on the other hand, a good guiding of the hinge member dueto the reliable retaining of the closing member in the housing and dueto a clearance-free displacement of the hinge member in the closingmember.

Though the spring hinge has a very economically produced stamped housingin which the unitary unit can easily and simply be secured, very hightechnical characteristics are achieved that up to the present could beachieved only with very high manufacturing costs.

The cost-effective manufacturing of a spring hinge is achieved byeliminating special guide means in the spring hinge housing due to aparticular shape of the closing member which also permitted to eliminatespecial locking elements used up to now for securing the hinge memberinside the housing.

I claim:
 1. A spring hinge for attaching glasses ear-pieces,comprising:an elongate housing having an open end surface; an elongatehinge member having an extension and a gudgeon and at least partiallyreceived in the housing; a spring member located in the housing, thespring member compressing upon pulling of the hinge member out; and aclosing member fixedly retainable in the housing and having an endsurface for closing the open end surface of the housing and defining arun-on surface of the closing member, and guide surface means defining,at least partially, an opening for receiving the hinge member and alongwhich the hinge member is longitudinally displaceable.
 2. A spring hingeaccording to claim 1 wherein the housing has a bottom.
 3. A spring hingeaccording to claim 2, wherein the bottom is formed integrally with thehousing.
 4. A spring hinge according to claim 1, wherein the housing haswalls of substantially the same thickness.
 5. A spring hinge accordingto claim 1, wherein the closing, spring and hinge members are assembledtogether as a pre-assembled unit before being mounted in the housing. 6.A spring hinge according to claim 5, wherein the spring member issecured on the closing member.
 7. A spring hinge according to claim 1,wherein the closing member has a catch nose, and wherein at least one ofa side wall and a top of the housing has a recess for receiving thecatch nose of the closing member.
 8. A spring hinge according to claim1, wherein the closing member has a substantially U-Shapedcross-section.
 9. A spring hinge according to claim 1, wherein thehousing and the hinge, spring and closing members form a pre-assembledsub-assembly.
 10. A spring hinge according to claim 1, wherein theclosing member is formed as a snap-locking member.
 11. A spring hingeaccording to claim 1, wherein the closing member has a length largerthan a height thereof, and a width smaller than the height.
 12. A springhinge according to claim 1, wherein the housing and at least one of theclosing member and the hinge member are formed as one of press metalpieces and shaped metal pieces.
 13. A spring hinge according to claim 1,wherein the housing and the closing and hinge members are formed of anickel-free material.
 14. A spring hinge according to claim 1, whereinthe housing and the closing and hinge members are formed of titanium.